Marine propulsion system



April 1, 1969 JEAN-PIERRE F. OSTERWALDER 3,435,800

I MARINE PROPULSION SYSTEM Filed May 15, 1967 Sheet of 6 I Fig.1 22\ 3 48 78 so 72 INVENTOR Jean-Pierre F. Oslerwalder m (1 mm max.

ATTORNEYS April 1, 1969 JEANPIERRE F. OSTERWALDER I 3,435,800

MARINE PROPULSION SYSTEM Filed May 15, 1967 Sheet 2 of6 Fig.4

INVENTOR Jeun-Pierr F. Oslerwulder ATTORNEY 5 April 1969 JEAN-PIERRE F. OSTERWALDER 3,435,800

MARINE PROPULSION SYSTEM Sheet 3 of 6 Filed May 15, 1967 INVENTOR Jean-Pierre |f;-Oflerwolder BY W (LSMJ%WW'A) 5804.01 wta ATTORNEY 8 April 1969 JEAN-PIERRE F. OSTERWALDER 3,435,800

MARINE PROPULSION SYSTEM Sheet 4 of6 Filed May 15, 1967 Jean-Pierre F. Oslerwulder Ducl group e BY g Wmmf $wm&% Mm

ATTORNEYS Aprll 1, 1969 JEAN-PIERRE F. OSTERWALDER 3,435,800

MARINE PROPULSION SYSTEM Filed May 15, 1967 Sheet 5 of e INVENTOF 106 114 Jean- Pierre Oslerwalde H 9 .9 wBlmjgwwiiQ i A TTORKE April 1, 1969 'JEAN-PIERREYF. OSTERWALDER 3,435,800

MARINE PROPULSION SYSTEM Sheet Filed May 15, 1967 BWENTQR Jean-Pierre F. psierwalder Fi g .12 figouzgsegws United States Patent 3,435,800 MARINE PROPULSION SYSTEM Jean-Pierre F. Osterwalder, 812 Cottage St., Vienna, Va. 22180 Filed May 15, 1967, Ser. No. 638,201 Int. Cl. B63h 5/00, N30

US. Cl. 115-28 Claims ABSTRACT OF THE DISCLOSURE A water propulsion system for propelling a ship through water by a sinuous undulating movement of a propulsor connected to the hull, the propulsor being secured at its periphery to the hull or on two sides and having its greatest amplitude at its central portion, the propulsor including (a) a flexible inelastic spine which may be a plurality of interconnected links forming a chain, the spine having positioned on each side thereof (b) a plurality of upper and lower opposed duct groups, each duct group including a plurality of tubular ducts which are preferably oval in cross sectional shape and secured to the spine by (c) webbing, such as nylon or metal web, and a closed hydraulic means periodically and continually supplying and withdrawing liquid alternately to opposed upper and lower ducts to produce bending and flexing in the propulsor to effect a sinuous, undulating movement, enclosed hydraulic means connected to the duct means including a multiphase pump generator means including a plurality of reciprocating piston and cylinder pairs 180 out of phase and a plurality of opposed pump generator cylinders receiving said pistons, a nozzle opening from each of the pump cylinders in fluid communication with the nozzle opening in the shell of a transformer distributor, the transformer distributor selected ducts and a plurality of stationary pistons secured to said covers, each said piston including a passageway in communication with a corresponding opening, a free piston within said shell and having a pressure face, said face formed to provide a plurality of cylinders receiving the stationary pistons whereby movement of hydraulic fluid in said pump generator is translated into corresponding expansion or contraction of the width of the ducts as opposed duct groups to efl ect the undulating sinuous wave-like movement of the propulsor.

This invention relates generally to a marine propulsion system. More particularly the present invention relates to a novel system for producing sinuous undulating wavelike traveling movements in a propulsor secured to the hull of a ship to propel the ship through water. The present invention also relates specifically to novel hydraulic system including motivating and distributing means for effecting the undulating sinuous movement of the propulsor.

Marine propulsion systems have not advanced substantially since the invention of the screw propeller. Any recent improvements and refinements have been directed primarily to the engines and fuels and the means for generating the power for the screw propeller.

Few if any improvements have been made to the screw propeller except in design and materials, yet the screw propeller remains as an ineflicient means for propelling a ship through the water. It has been found that the energy generated by the propeller is dissipated into various directions and is not concentrated completely or exclusively 3,435,800 Patented Apr. 1, 1969 along the most useful vector. The propeller contacts the water medium eifectively only in a small area, and it is not possible to create any substantial pressure against the water in the line of the shaft axis, primarily because of the multidirectional movement of the water in the area of the propeller. For example, the Water flowing away from the area of pressure along the line of least resistance to the area of the lowest pressure-that is, the suction area immediately in front of the propellerproduces a wasteful circumferential movement which robs efliciency from the propeller propulsion.

Man has studied the movement of fish and aquatic animals in an effort to develop eflicient means for propelling ships through the water, but has never designed a practical system. Recent US. patents have been issued to Kicenius, 3,118,639, Momsen, 3,154,043, and Clark, 3,221,702, and others in an effort to simulate the movement of fish and aquatic animals in water; however, these prior art systems have been found to be ineffective for commercial use.

It is the principal object of the present invention to provide a marine propulsion system which utilizes a propulsor having an undulating sinuous wave-like motion for propelling ships through water.

Another object of the present invention is to produce the sinuous undulating movement of the propulsor while attached to the hull of a ship.

This invention also has for an object the provision of a closed hydraulic system which elfects periodically and continually undulating and sinuous wave-like motion in the propulsor.

A further object of the present invention is the provision of a propulsor which provides a maximum amplitude substantially amidships and which diminishes in amplitude towards the port and starboard sides of the ship.

Another and more particular object of the present invention is the provision of a plurality of duct groups including individual ducts which are secured to a flexible inelastic spine of the propulsor.

Another object of the present invention is the provision of a closed hydraulic circuit which includes a pump generator and a transformer distributor in fluid communication with selected and opposed pairs of duct groups for admitting and withdrawing hydraulic fluid for alternate out of phase expansion or contraction of a duct group compared to its opposed duct group in an opposed pair of duct groups to produce the undulating sinuous traveling wave-like movements of the propulsor.

These and other objects and advantages of the present invention will become apparent to those skilled in the art, from the following description when read in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a across sectional view taken along a longitudinal line amidships of a ship hull and embodying the propulsor of the present invention;

FIGURE 2 is a cross sectional view taken along lines 22 of FIGURE 1;

FIGURE 3 is a cross sectional perspective view partly broken away showing the details of the means for securing the propulsor to the ships hull;

FIGURE 4 is an enlarged cross sectional view partly broken away, similar to that of FIGURE 3, but illustrating in more detail the hydraulic system connection to the ducts and the resilient shock absorbers in contact with the ships hull;

FIGURE 5 is a perspective view, partly broken away and partly in section, of the flexible inelastic spine and its connection at the forward position on the hull of the ship and also illustrating the novel ducts of the present invention and their securing means to the flexible, inelastic spine;

FIGURE 6 is an enlarged perspective view, partly broken away, of opposed ducts of opposed upper and lower duct groups illustrating the Webbing securing the ducts to the flexible, inelastic spine (not shown in this figure);

FIGURE 7 is a fragmentary cross sectional view of the propulsor shown in FIGURE 4, illustrating the plurality of ducts, flexible, inelastic spine, and the hydraulic fluid in the ducts eflecting the sinuous undulating movement of the propulsor;

FIGURE 7 is also a schematic illustration of an 8-phase pump generator which motivates the hydraulic fluid through the closed hydraulic system.

FIGURE 7 is also an illustration in perspective of the distributor transformer of the present invention and also illustrating the position of the connections from the nozzle openings of the transformer distributor to selected ducts forming a duct group in the propulsor.

FIGURE 7 also shows a cross-sectional view and an exterior view of a transformer distributor and an illustration of the specific connections of the nozzle openings to opposed ducts of a duct group on the opposite side of the propulsor with respect to the duct group of the transformer distributor;

FIGURE 8 is a schematic illustration of the pump generator and the hydraulic connections from opposed cylinders of the pump generator to opposed duct groups on. the propulsor.

FIGURE 9 is an illustration of a modified form of the transformer distributor of FIGURE 7 and combines in one unit the operation of two transformer distributors.

FIGURE 10 is a schematic cross sectional view similar to that of FIGURE 2 except that water is in contact with both upper and lower sides of the propulsor.

FIGURE 11 is an enlarged view, partly broken away, of that portion of FIGURE 10 illustrating the connection of the propulsor of the ships hull.

FIGURE 12 is a front elevational view illustrating the application of the invention to a catamaran type ship.

In FIGURES 1, 2 and 3 there is shown a ship hull 20', a conventional ship structure 22 and a conventional ship floor 24. Positioned and secured to the ships hull is a flexible pro pulsor 26 forming air space 27 between the floor 24 and the propulsor. The propulsor is secured fore and aft by securing means 28 and to port and starboard side by securing means 30. The propulsor, therefore, is fixed throughout its periphery to the ships hull. The undulating sinuous wave-like movement of the propulsor, as shown in FIGURE 1, is attained by the propulsor in maximum amplitude along amidships line of the ship and at an elfective distance from the fore and aft securing means 28. The maximum amplitude of the propulsor, as shown in FIGURE 1, is both in the downward direction 32 and in an upper direction shown at 34. It should be understood that the showing of the wave-like motion in FIGURE 1 is schematic and does not necessarily represent the true wave-like motion of the pro poulsor nor the number of undulations that are produced in the propulsor.

In principle the concept of the propulsor of the present invention as a means for propelling a ship in water is based upon the fact that the undulating form of the propulsor will propel the water in the direction of the undulating movement of the propulsor and produce a corresponding reaction which moves in a direction opposite to the movement of the water. It has been found that unlike the conventional propeller, which produces turbulence, there is virtually no possibility for the water held in trough 36 of FIGURE 1 to escape the pressure of the propulsor either laterally or downwardly. Accordingly, as

.4 the Water held in trough 36 is moved in the direction of the arrow 38, by reason of the maximum amplitulde in the upward direction at 34 moving to the left in FIGURE 1, the ship will be propelled in the direction as shown by arrow 40.

It should be understood that the volume of water displaced and the rapidity of this displacement determines in part the effective travel of the ship through the water. More particularly, the amplitude of the undulation vertically, as illustrated at 42, the wave length or distance between adjacent points 'of maximum amplitulde, as illustrated at 44, the frequency of the cycle or movement of the propulsor and the width and length of the propulsor all bear upon the volume of water moved relative to the ship and therefore all greatly 'aflect the speed of the ship in the water.

One aspect of the present invention is the novel means devised for effecting the undulating and sinuous wave like movement of the propoullsor in an eflicient, economical and practical manner.

In FIGURES 5, 6 and 7 there is shown the details of the Jpropulsor 26 and the plurality of upper and lower ducts 46 and 48, respectively, filled with hydraulic fluid 50 form a closed system, the webbing S2 securing the ducts 46 and 48 to a flexible and inelastic spine 54, formed of a plurality of interconnecting links 56.

As best shown in FIGURE 5, the propulsor 26, which includes the flexible, inelastic spine 54, is aflixed by the securing means 28 to the hull of 20 of the ship through the use of suitable threaded members 58. The spine is composed of a plurality of inner connecting links 56, secured together by rods 60, which permit the links to attain the necessary flexibility for achieving the amplitudes required to eifectively move the ship through the water. The rods 60 are sufficiently flexible over their length in order that the securing of the propulsor at the sides to the ships hull at 30 nevertheless permits the decreasing amplitude from the maximum amplitude at the amidships position to the point on the propulsor that is connected to the ships hull at 30, which has substantially no amplitude. The rods 60, therefore, are preferably formed from sturdy material, such as steel, reinforcel nylon, reinforced epoxy which nevertheless has sufficient flexibility to permit the sinuous undulating movement of the propulsor. The links 56 may also be composed of steel, if so desired.

The ducts 46 and 48 forming the upper and lower ducts respectively are the means for creating the flexure or bending in the propulsor, as best seen in FIGURES 1, 7 and 8. In FIGURES 5 and 7 the ducts 46 and 48 are of a substantially oval shape and are made of a flexible and deformable elastic material capable of withstanding pressures of up to several thousand pounds per square inch. Suitable material for the ducts would be reinforced rubber or plastic compositions presently availalble commercially.

The shape of the ducts 46 and 48, being initially substantially oval, is deformed into a more circular shape upon the supply of additional liquid to the ducts. At this time the ducts are expanded in width across their minor axes indicated at 62 and 64 of the upper and 'lower ducts 46 arid 48.

The ducts are held to the flexible inelastic spine 54 by suitable webbing 52, which may be of metal or woven synthetic fiber, such as nylon, polyethylene, terephthalate or polypropylene, etc. In FIGURE 6 the preferred manner of wrapping of the webbing 52 around the ducts 46 and 48 is clearly shown with the flexible spine 56 omitted from this view for purposes of clarity. But, as can be clearly seen in FIGURE 7, the webbing 52 is intertwined between the spaces in the flexible spine '54 to securely position the ducts to the spine. It should be understood that this particular means of maintaining the ducts in posiiton on the spine is not critical to this invention.

The propulsor in its finished form must be impervious to water in which the ship sails. Accordingly, the propulsor is provided with an upper 66 and a lower 68 water impervious skin made of suitable plastic or rubber, which is flexible and possesses great strength to resist the forces to which the propulsor is inherently subjected.

The propulsor is secured on the port and starboard side to the hull between fixed plates 70 and 72, which form the upper and lower plates for attachment to the hull. As best shown in FIGURE 3, the lower plate 72 is secured to the hull 20 by suitable connectors 74. The upper and supporting plate 70 is secured to the athwartship propulsor supporting frame 76 by any suitable connecting means such as screws 74. The frame 76 is permanently fixed to ship structure 22. Porting 77 is provided in the frame and ship structure 22 to equalize the pressure in the air space 27. The propulsor is secured between the upper and lower plates 70 and 72, with resilient shock absorbers 78 and 80 provided, which may be integral with the upper and lower skins 66 and 68 of the propulsor or suitably bonded to the skins to provide a permanent structure which will assure the securing of the propulsor to the ship. Of course, if the shock absorbers 78 and 80 are not integral with the upper and lower skins 66 and 68 of the propulsor, the bonding or adhesive used must be water tight. Also, to assure against leakage and to provide leak-tightness, suitable gaskets 82 should be provided between the securing plates 70 and 72 and the ships structure 20 and 76.

One of the features of the present invention is that the hydraulic system used to supply and withdraw the hydraulic fluid from the ducts be a completely closed system. It has been found that a pluralit of adjacent ducts on the same side of the spine 54, which arbitrarily may number 8, can 'be referred to as a duct group. In accordance with the present invention, a duct within a particular duct group acts in the same manner as every other duct in that particular group-that is, either all the ducts of a particular group are in extension or in contraction at the same time. In FIGURES 7 and 8, duct groups are identified by letters a, b, c, d, e, f, g and h, and every duct group labeled with the same identifying letter is designed to act in precisely the same mannerthat is, be in expansion or in contraction, due to the supplying or withdrawing of hydraulic fluid. Opposing duct groups on opposed sides of the flexible spine 54 act 180 completely out of phase with each otherthat is, for example, while the ducts of group a are being supplied with hydraulic fluid, the ducts of group e are having the fluid withdrawn. The ducts of group a, therefore, will have their maximum expansion at exactly the same time that the ducts of group e have their maximum contraction. In this manner, as shown in FIGURE 7, when additional hydraulic fluid is supplied to ducts 46 of group a, the increased volume of fluid will necessarily expand the width of the ducts in the direction of the duct minor axis 62 and at the same time ducts 48 of group e will experience a reduction in the hydraulic fluid, causing a reduction in the Width along duct minor axis 64. It is obvious, with the expansion above the spine 54 and a contraction below, that the spine will flex or bend in the manner shown in FIGURE 7, and similarly as shown overall in FIGURE 8 for those duct groups in which a is the upper duct group and e is the lower duct group.

At precisely the same time that the propulsor is flexed in the manner described by duct groups a and e, opposed duct groups b and f, c and g, d and h, e and a, f and b, g and c and h and d are expanded or contracted in accordance with the volume of fluid received in their respective ducts, causing the periodic undulations or sinuous wave-like movements, shown in FIGURES l, 2 and 8.

In order to control the periodic continual undulations of the propulsor, the volume of hydraulic fluid in all of the duct groups is continuously changed in accordance with the desired cyclical undulating sinuous wave-like movement of the propulsor.

To attain the desired cyclical movement, several of the novel features of the present invention are incorporated into a novel hydraulic system which comprises principally a multiphase pump generator 84, shown schematically in FIGURES 7 and 8, and novel transformer distributor 86, which receives the hydraulic fluid from the pump generator 84 and distributes the hydraulic fluid to the particular duct group and individual ducts associated with each transformer distributor.

The pump generator 84 is the means responsible for synchronizing the volume displacement of the hydraulic fluid in the ducts, which in turn results in the undulating movement. In the representation in FIGURE 7, eight ducts form a duct group, and in FIGURE 8 one Wave length 44 is arbitrarily broken down in fore and aft length into eight pairs of opposed duct groups. Of course, the number of lpairs of duct groups can be varied from that illustrated ere.

The multiphase generator 84, as shown in FIGURE 8, includes eight cylinders-88A, B, C, D, E, F, G and H- one for each duct group, a through h, respectively, the volume in duct groups having the same letter designation (ex. a) are controlled by the same cylinder (ex. A) of the pump generator and will accordingly expand or contract in unison. The opposed duct group (ex. a) in any duct pair will be 180 out of phase with the duct group (ex. e) in the same pair. To accomplish this the 8-phase pump generator 84 has each of the eight cylinders in fluid communication with its corresponding duct group. It will be evident that there are four pairs of opposed cylinders which are 180 out of phase with each other, and accordingly will supply opposed duct groups. Cam shaft 90 in a conventional manner will operate the corresponding pistons in each cylinder, in order that opposed cylinders may be out of phase with each otherthat is, that one opposed cylinder may be withdrawing hydraulic fluid while the other opposed cylinder is supplying fluid to its corresponding duct group.

As shown, for economy and operation, each cylinder can supply two pairs of duct groups, which is all that is necessary for a propulsor equal in length to two wave lengths, as shown in FIGURE 8.

One of the features of the present invention is that the quantity of hydraulic fluid in a cylinder and its corresponding duct group remains constant. The volume or capacity of the system to receive the quantity of fluid varies by means of the expansion or contraction of the ducts and the movement of the piston within the cylinder. It is obvious that as the piston is moved to diminish the available hydraulic fluid volume in the cylinder, the hydraulic fluid will force the corresponding ducts to expand. At the same time the opposed cylinders would be withdrawing fluid so that the corresponding ducts would contract.

To properly distribute the hydraulic fluid from the cylinder to the respective duct in any duct group, each duct group is provided with a transformer distributor 86, such as that illustrated at 862, which is secured to its respective cylinder by pipe connection 92 and is in fluid communication with the transformer distributor by means of nozzle opening 94 leading to passageway 96 formed in stationary piston 98. This stationary piston is suitably secured in top cover 100 closing a cylindrical shell 102 at one end and with a bottom cover 104 at the other end. Positioned in the bottom cover 104 of the transformer distributor are a plurality of nozzle openings 106 connected to suitable conduits 108 that are in turn connected to the respective ducts by suitable fluid connectors 110, as shown in FIGURE 4. Nozzle openings 106 are in fluid communication with passageways 112 in corresponding stationary pistons 114, which as shown in FIG URE 7 are concentric to the stationary piston 98 at the opposite end of the transformer distributor. Within the shell 102 is a free piston 116, which is designed for movement towards bottom cover 104, in accordance with the movement of the corresponding piston in the cylinder 88 to which the particular transformer distributor is in fluid communication. The free piston 116 is provided in its bottom pressure face with a plurality of cylinders 118 for receiving the stationary pistons 114. An upper pressure face is provided with cylinder 120 which cooperates with and receives the stationary piston 98. Suitable seals are provided between the piston and the cylinders for effective operation.

The operation of the transformer distributor is such that as the corresponding piston of the pump generator moves in a direction to supply hydraulic fluid to the transfomer distributor through pipe 92, nozzle opening 94, passageway 96 and through stationary piston 98 of the cylinder 120, free piston 116 will be moved towards the bottom cover 104 and the hydraulic fluid cylinders 118 will be forced through passageway 112 in stationary pistons 114 through nozzle openings 106 into the respective conduits 108 to each duct of the duct group e, for instance, as shown in FIGURE 7.

FIGURE 9 illustrates a modified form of the transformer distributor 122 in that it combines the work of two 180 out of phase transformer distributors such as those of 86a and 86e. As shown, the same pipe connections 92a and 92e are utilized to provide fluid communication through nozzles 94a and 94:2 to stationary pistons 98, positioned in covers 124 and 126. Each cover is also provided with nozzle openings 1062 and 106a in corresponding passageway 112 in a manner similar to that described for transformer distributor 862. The free piston 128 is similar to that of 116, except that it is provided with cylinders 120 and 118 on the same pressure face side of the piston. It should be noted, however, that to effectively combine the operation of two transformer distributors, the operation of the conduits 92a and 92e operate on the opposite side of the free piston 128 as the opposed conduits 108a and 108e, respectively.

In FIGURES 1, 2 and 3, water is on only the underside of the propulsor and the space 27 is air space freely permitting the undulating movement of the propulsor. However, it is within the scope of this invention to provide for the dual action of the propulsor upon water positioned on both seats of the propulsor.

In the construction in FIGURES l and 11, water is admitted through a pair of openings 130 in the hull fore and aft of the propulsor. The propulsor is secured to the hull and its supporting structure 22 in essentially the same manner as previously set forth, except that upper and lower securing plates 132 and 134 are provided with vertical flanges 136 and 138, suitably secured to the ships hull by connectors 74. The water W is, therfore, admitted to both sides of the propulsor to substantially increase the elficiency and effectiveness of the undulating sinuous movement, since in one wave length substantially twice the volume of water will be moved, as in the embodiment of FIGURES 1 through 3.

FIGURE 12 shows the propulsor mounted between the two hulls of a catamaran type of ship. The propulsor is only fixed on the side by connector 74 similar to the one shown on FIGURE 11.

It should be emphasized that the fore part of the propulsor is free and cuts through the water. The fore and aft part of the propulsor are not fixed to the ship and are able to assure the maximum or full amplitude amidships fore and aft along the propulsor but effectively has a zero amplitude at the two sides adjacent connector 74.

It will be evident from the foregoing detailed description that there are a number of changes, adaptations, and modifications of the present invention which come within the province of those skilled in the art. However, it is intended that all such variations not departing from the spirit of the invention be considered as within the scope thereof as limited solely by the appended claims.

I claim:

1. A water propulsion system for a ship having a hull comprising:

a propulsor forming a flexible, continuous membrane and having a periphery and a central portion within said periphery,

said propulsor being substantially secured at least a portion of its periphery only to said hull and freeat its central portion to move in an undulating, sinuous movement,

hydraulically deformable duct means positioned on said propulsor for providing undulating sinuous movement to said propulsor,

said duct means including a plurality of upper and lower opposed duct groups, each duct group comprising a plurality of tubular ducts, and having a substantially oval shape,

said propulsor including a flexible, inelastic spine positioned between said upper and lower duct groups,

securing means holding said ducts to said spine,

hydraulic means connected to said duct means to selectively and continually vary the quantity of liquid in said ducts, thereby controlling the shape of selected ducts to effect a desired sinuous movement to said propulsor whereby to propel the ship through water.

2. The water propulsion system of claim 1, wherein each of the ducts of an upper or lower duct group is periodically and reversely deformed with respect to each of the ducts of opposed lower or upper duct group respectively in their fore and aft width directions to expand and contract and thereby produce a periodic sinuous movement to said propulsor.

3. The water propulsion system of claim 1, wherein said flexible inelastic spine comprises interconnecting links and wherein said securing means includes a web surrounding said ducts and interconnecting said ducts to said spine.

4. The water propulsion system of claim 1, wherein said hydraulic means includes in fluid communication (a) a multiphase pump generator means and (b) a transformer distributor means in fluid communication with said ducts.

5. The water propulsion system of claim 4, wherein said transformer distributor means includes a cylindrical shell and top and bottom covers, said shell having a nozzle opening in fluid communication with said pump-generator means, a plurality of nozzle openings in fluid communication with selected ducts, a plurality of stationary pistons secured to said covers, each said piston including a passageway in communication with a corresponding opening, a free piston within said shell and having a pressure face, said free piston having a plurality of cylinders provided in said pressure face for receiving said stationary pistons.

6. The water propulsion system of claim 5, wherein said multiphase pump generator means includes a plurality of reciprocating piston pairs out of phase, a plurality of opposed pump cylinders receiving said pistons, a nozzle opening from each said pump cylinder in fluid communication with said nozzle opening in said shell, each nozzle opening being in fluid communication with a selected first duct group and a nozzle opening on a mutually opposed cylinder housing, a 180 out of phase piston being in fluid communication with a second duct group, said second and first duct groups being mutually opposed on either side of said spine and periodically and reversely deformed.

7. The water propulsion system of claim 1, wherein a resilient shock absorbing member is secured on each side of said propulsor at the periphery for securing said propulsor to the hull.

8. The water propulsion system of claim 1, wherein the propulsor is so secured to said hull that it possesses its 9 greatest amplitude of undulation amidship and amplitude diminishes effectively to zero at the periphery.

9. The water propulsion system of claim 1, wherein said propulsor is secured at its entire periphery to said hull.

10. The water propulsion system of claim 1, wherein 5 1 0 References Cited UNITED STATES PATENTS 3,118,639 1/1964 Kiceniuk 1150.5 X'R 3,279,416 10/1966 Cockerell 115-28 ANDREW H. FARRELL, Primary Examiner.

US. Cl. X.R. 

